This invention relates generally to the field of biological remediation, that is, the degradation of hydrocarbons and other organic matter utilizing microorganisms, primarily bacteria, to convert hazardous or undesirable organic matter into environmentally safe byproducts. More particularly, the invention relates to circumstances and applications where it is desirable to provide biological remediation on a long-term basis.
It is well known that microorganisms such as bacteria can be used to remediate undesirable or hazardous matter, waste products, pollution, etc. The microorganisms utilize the undesirable matter as a food source, converting the matter into safe byproducts that can be released into the environment. Such remediation has long been used in septic tank systems, where the microorganisms convert the human waste matter into non-harmful compositions that can be released into the environment. Many other circumstances can be remedied by biological remediation, including oil spills, grease traps, filters and the like, wherein the microorganisms are presented to the undesirable organic matter, such as when absorbent pads containing microorganisms are placed into water at the site of an oil spill, or wherein microorganisms are contained in absorbent filter media pads or bags located in a drain.
In many instances it is desirable to have the microorganisms present on an on-going, long-term basis, such as for example in storm water basin filters, where it is impossible to predict when oil or other hydrocarbons may be washed into the storm water system, or in filter drain traps in restaurants, where grease and oils are constantly being flushed into the drain. To address this, it is known to encase or encapsulate the microorganisms such that the coatings or binders dissolve or degrade over time, releasing or exposing the microorganisms in a generally steady manner over an extended period of time, often referred to as time release capsules or the like.
Examples of methodologies of biological remediation and devices incorporating microorganisms for biological remediation are disclosed for example in U.S. Pat. No. 3,242,055 to De Lucia, U.S. Pat. No. 3,860,490 to Guttag, U.S. Pat. No. 4,810,385 to Hater et al., U.S. Pat. No. 5,275,943 to DiTuro, U.S. Pat. No. 5,348,803 to Schlaemus et al., U.S. Pat. No. 5,807,724 to Resnick, U.S. Pat. No. 5,820,762 to Bamer et al., U.S. Pat. No. 5,879,932 to Van Erdewyk, U.S. Pat. No. 6,573,087 to Lehr, U.S. Pat. No. 7,166,221 to Young et al., and U.S. Pat. No. 7,429,221 to Paoluccio et al., the disclosures of which are expressly incorporated herein by reference, in particular to provide examples of formulations for encased or encapsulated microorganisms suitable for biological remediation.
All of the known systems utilize a time release mechanism for distributing or exposing the microorganisms to allow for remediation of the hazardous or undesirable hydrocarbons, and this presents a problem in many circumstances. Usually the colony of microorganisms present in a pad, filter or other carrier member has a limited lifespan, such that after a period of time the effectiveness of the biological remediation is diminished or eliminated entirely. This means that periodically the carrier member and its microorganisms must be removed and replaced by a new carrier member with a new colony of microorganisms. The costs to provide replacement carrier members and the labor costs involved in replacing the spent carrier members can be high, especially in circumstances where a large number of sites are involved. For example, in storm water systems wherein hydrocarbon-consuming microorganisms are provided as part of the filtering mechanism in storm drain basins, a given system will have hundreds or even thousands of storm drains. For systems containing microorganisms, a quarterly or monthly replacement of the microorganism-containing filters must be performed instead of the annual maintenance typically required to replace or clean the storm drain filter system in non-microbe-containing systems, thereby increasing the costs multi-fold.
It is an object of this invention to provide a methodology and related system and structures for accomplishing the methodology, whereby a plurality of carrier members, such as tablets, capsules or containers, containing microorganisms are retained in situ at locations where biological remediation of hazardous or undesirable organic matter may be required over extended periods of time, whereby the carrier members are structured such that the microorganisms within one or a first set of carrier members are released or exposed to begin remediation at one point in time, while the microorganisms within another one or a second set of carrier members are released or exposed to begin remediation at a later time than the first set, and the microorganisms within one or third set of carrier members are released are exposed to begin remediation at a later time than the second set, etc. It is another object to provide such a methodology and related systems and structures whereby the long-term staggered release or exposure of the microorganisms is customizable, such that the staggered release can be periodic, such as monthly or quarterly, or non-periodic in reaction to predictable changing conditions, such as varying seasonal requirements. It is another object of this invention to provide such a methodology and related systems and structures whereby nutrients, e.g., food and/or water, necessary for the survival of the microorganisms upon release are provided within the carrier members containing the microorganisms or are provided in companion carrier members, such that the food, nutrients or water are released in conjunction with the periodic release of the microorganisms, thereby ensuring the survival of the microorganisms in the event that no external food, nutrients or water are present in the environment upon their release.